Math Problem Statement

A 6-sided die with equal chances has the numbers 1, 2, 3, 4, 5, and 6 written on its faces. The die is tossed twice, and the numbers obtained are recorded accordingly. What is the maximum number of ways for the sum of the two recorded numbers to be a number that has 2 factors only?

Solution

To solve this problem, we first note the key details:

Problem Breakdown:

  1. A standard 6-sided die contains numbers 1,2,3,4,5,61, 2, 3, 4, 5, 6.
  2. The die is rolled twice, so the possible sums range from 22 (1+1) to 1212 (6+6).
  3. We need to find the maximum number of ways to get a sum that has exactly 2 factors, meaning the sum must be a prime number.

Step 1: Identify the prime numbers in the range

The prime numbers between 22 and 1212 are: 2,3,5,7,112, 3, 5, 7, 11

Step 2: Determine the pairs of dice rolls for each prime sum

Now, for each prime sum, find the combinations of rolls that result in that sum:

Sum = 2

  • (1,1)(1, 1) → 1 way

Sum = 3

  • (1,2),(2,1)(1, 2), (2, 1) → 2 ways

Sum = 5

  • (1,4),(2,3),(3,2),(4,1)(1, 4), (2, 3), (3, 2), (4, 1) → 4 ways

Sum = 7

  • (1,6),(2,5),(3,4),(4,3),(5,2),(6,1)(1, 6), (2, 5), (3, 4), (4, 3), (5, 2), (6, 1) → 6 ways

Sum = 11

  • (5,6),(6,5)(5, 6), (6, 5) → 2 ways

Step 3: Calculate the maximum

The sum 77 has the maximum number of combinations (6 ways).

Final Answer:

The maximum number of ways for the sum of the two recorded numbers to be a number with exactly 2 factors is 6.

Would you like a detailed explanation of why these sums correspond to specific dice rolls, or help with related questions? Here are five questions for further exploration:

  1. What are the total number of outcomes when rolling two dice?
  2. How can the total probability of rolling a prime number as the sum be calculated?
  3. What is the probability of rolling a sum of 77?
  4. Can this process be extended to dice with more faces (e.g., an 8-sided die)?
  5. How do probabilities change when restricting outcomes to odd sums only?

Tip: Prime numbers are key in many probability problems because they often limit the number of viable combinations—an important tool in problem-solving

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Math Problem Analysis

Mathematical Concepts

Probability
Prime Numbers
Combinatorics

Formulas

Sum = a + b (where a, b are outcomes of dice rolls)

Theorems

Definition of prime numbers

Suitable Grade Level

Grades 9-12